Research On The Degradation Performance Of Modified Titanium-based Lead Dioxide Electrode For Phenol-containing Wastewater

Chemical industry is developing rapidly now,which caused pollution problems because of the amount of complex pollutants was discharged into the environment,being the bottleneck for the sustainable development of it.Among of the numerous treatment methods,the Electrochemical oxidation technology(AEPOs)have attracted wide attention from researchers on all walks of life for the treatment of the stubborn pollutants because of the strong oxidizing properties.Electrode materials are the core of electrode catalytic activity.However,the development of electrode materials is currently facing great challenges.Therefore,a method which could improve the catalytic activity and stability of electrodes is urgently demanded for domestic and foreign researchers at present.PbO2 electrode was considered to be better electrode materials contributed to the relatively high conductivity,and strong corrosion resistance compared to other electrodes.To improve the stability and reactivity of the electrode,modified the electrode by the base layer and the introduction of active materials,was mainly investigated in this article.The research content and results are as follows:(1)the modification of PbO2 electrode was started from introducing into blue nanotubes(Blue-TiO2-NTs)on the basis of the titanium plate to improve the conductivity of the electrode.The β-PbO2 active layer was formed on the surface of the nanotubes by electrodeposition,and the β-PbO2 active layer was optimized by using hydroxylated multi-walled carbon nanotubes(CNT),and orthogonal experiments were designed to optimize the electrode preparation conditions.It was evaluated that the catalytic reaction performance of the PbO2 electrode was better,and the resistance was reduced,through the electrochemical performance test of it.The different factors of the degradation of phenol wastewater were investigated,when the CD of 25 mA/cm2,and the electrolyte concentration of Na2SO4 was 0.1 M,and showed a better effect on removing the phenol(100 mg/L)under neutral conditions,the removal reached 97.59%after 180 minutes of degradation,and the removal rate of COD was 89.29%at 240 minutes.It was indicated that the electrode has strong stability which service life up to 1228.8 h and after 15 consecutive electrolysis experiments,the removal of phenol decreased by 4.82%.(2)the surfactant and Ce elements were added to the PbO2 deposition solution,the doping amount and surfactant type were optimized,and it was evaluated that the PbO2 electrode has higher reactivity.It was observed that the doping of Ce elements made a large number of protrusions on the surface of the electrode through SEM.The influence of different operating conditions of electrolysis experiment for the removal rate of phenol was studied which could be observed that the CD of 25 mA/cm2,and the concentration of Na2SO4 was 0.15 M and the initial pH value was 9 as the best conditions for phenol degradation.Under the optimal conditions,the removal rate of phenol was 96.39%at 120 min,and the degradation efficiency of COD reached 97.76%after 240 min.It has great significance for practical application,result from it was evaluated that the service life was 1228.8 h,and the removal rate of phenol is only reduced by 2.43%after 15 times of use under the same conditions.(3)Two optimized electrode degradation mechanisms was explored,and the free radical masking experiment shows that the main active substance that attacks pollutants was OH.